Heating apparatus



Sept; 14, 1943. w. s. LANDON HEATING APPARATUS Filed March 5, 1940 5Sheets-Sheet 1 INVENTOR W066i. A]. Maw

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Sept. 14, 1943.

w. s. LANDON gmnm APPARATUS 'Filed March-5, 1940 5, Sheets-Sheet 2 I l ll I I l I l l l l .4 I l l I Fla-3 & e aw 4| I 45 INVENTOR 46 25 M K MA45) AT row-Ev" W. S. LANDON HEATING APPARATUS Filed March 5, 1940 Sept.14, 1943.

5 Sheets-Sheet 4- nU m Sept. 14, 1943. w. s. LANDON HEATING APPARATUSFiled March 5, 1940 5 Sheets-Sheet 5 INVENTOR Patented Sept. 14, 1943UNITED STATES PATENT OFFICE HEATING APPARATUS Walter S. Landon, Detroit,Mich, asslgnor to Detroit Lubrlcator Company, Detroit, Mich. acorporation of Michigan Application March 5, 1940, Serial No. 322,414

15 Claims.

My invention relates generally to heating apparatus and moreparticularly to apparatus for controlling the flow of liquid fuel to ahydroxyla- A further object is to provide an apparatus which acts toprovide natural draft flow of air to the burner upon failure of theforced air supplying means. 1

A further object is to provide means for interconnecting the aircontrolling means with the fuel controlling means to provide at alltimes the correct proportion of fuel and air to the burner.

The invention consists in the novel arrangement and construction of theparts to be more fullydescribed hereinafter and the novelty of whichwill be particularly pointed out and distinctly claimed.v

In the accompanying drawings, to be taken as a part of thisspecification, I have fully and clearly illustrated a preferredembodiment of my invention, in which drawings:

Figure 1 is a schematic view of a heating system employing a liquid fuelburner and showing my control apparatus and. the control systemtherefor;

Fig.2 is a top plan view of the control apparatus with certain of theparts removed in order to show more clearly a portion of the controllingmeans and showing a simplified control circuit therefor;

Fig. 3 is a front view in elevation of the apparatus with a portion ofthe fuel controlling means in vertical section;

Fig. 4 is a view substantially along the line 4-4 of Fig. 2 looking inthe direction of the arrows;

Fig. 5 is a view substantially along the line 5--5 of Fig. 2 looking inthe. direction of the arrows;

Fig. 6 is a schematic view of a modified form of a heating systemshowing my burner control apparatus in conjunction with a modified fluidcontrol system;

Fig. '7 isa view in central vertical section of the space temperaturesensitive element of Fig. 6 and showing the adjusting means;

Fig. 8 is a view of the modified control apparatus of Fig. 6 taken incentral vertical section through the control chamber, the fuel chamberand the power element and also aview showing in elevation the controlsystem bulb means;

Fig. 9 is a top plan view of a modified form of the controllingapparatus;

Fig. 10 is a view substantially along the line l0|ll of Fig. 9 lookingin the direction of the arrows and with the fuel chamber partly brokenaway and partly shown in section, and

Fig, 11 is a view substantially along the line H--ll of Fig. 9 lookingin the direction of the arrows with the control chamber and fuel chamberremoved but showing the air supplying means connected thereto.

Referring to the drawings -by-characters of reference, the numeral Iindicates generally a heating apparatus for a hydroxylation type burner2 to be supplied by. fuel and air through conduits .2 and 2respectively, leading from a control device 3. The products ofcombustion from the burner 2 pass upwardly into the combustion chamber 4and outwardly therefrom through a central aperture 4 of the chamber 4and pass downwardlybetween the outer wall of the combustion chamber 4and a shell 5 which separates the products of combustion from buttransfers the heat to the air within a plenum chamber 6. The spentcombustion products then pass .to atmosphere througha stack 6 which iscontrolled by means of a damper 8'. A constantly operating aircirculating fan I is driven by an electric motor 8, connected thereto bymeans of a pulley and belt drive 9 and extracts air from the space H) tobe heated through an outlet duct means H which leads to a fan inletchamber l2. Air is forced outwardly by the fan 1 through a duct l3 intothe furnace plenum chamber 6 where it is heated due to its contact withthe heated furnace shell 5 and flows therefrom through a duct Hi to thespace It).

The operation of the burner 2 is controlled by means of a unique roomthermostat, diagrammatically shown at IT, and described in detailhereinafter. The thermostat ll acts to maintain a predeterminedtemperature within the space l0. Excess heating of the plenum chamber 6is prevented by. means of the usualhigh tempera-. ture limitcontrol l8which acts tii reduce the fuel flow to the burner 2 upon occutrence' ofa predeterminedhigh temperature in the chamber 6 to prevent overheatingthereof. Fuel oil is stored in an oil tank I9, and flows therefromthrough a conduit 19, and through a constant level device IQ, andthrough the conduit 20, to the control means 3. The fuel oil is meteredby the control means 3 and flows therefrom through the conduit 2 to thefire pot 2|. The necessary air for combustion of the fuel oil issupplied by the fan 1 and flows through a conduit 22 which opens intothe duct l3 through an orifice 23 and leads to the control means 3 wherethe .air is regulated in proportion to the quantity of fuel oil beingsupplied to the burner. The regulated air then flows through theairconduit 2 to the Positioned in one wall of the conduit 22 is an airpressure regulator or shutter'24 which acts to maintain a substantiallyconstant air pressure within the conduit 22 at all times. Should thepressure within the conduit begin to exceed the predetermined desiredpressure, the shutter 24 will open to allow the excess air to escape andshould the pressure begin to decrease below atmospheric pressure, theshutter 24 will open to allow atmospheric pressure within the conduit22.

The control means 3 preferably comprises a chambered housing or hollowcasing member 25 having a chamber 26, with an inlet 21 connected to theconduit 22, and an outlet 28 connected with the conduit 2 (see Fig. 1).'Flow through the chamber 26 is controlled by a plate-like shutter 29positioned within the chamber 26. The top portion of the shutter 29 isrigidly secured to a shaft 29, spaced from but positioned adjacent thetop wall of the chamber 26 and which is journalled at either end inopposite end walls 36, 3|

of the chamber 26. The shutter 29 when inert hangs downward acros theinlet 21 and normally acts to close the inlet 21 to flow of air but isurged in an open direction (see Fig. by the pressure of the air withinthe conduit 22. The shutter 29 preferabl has a large aperture 32therethrough. A pair of ears 33 (only one of which thereof.Substantially midway betweenthe bottom wall 4| and the top wall 40, theside walls 36, 42, 43 and 44 have an upwardly facing shoulder 59 againstwhich is positioned a plate-like member 5|. The member 5| ha an aperturethrough which the valve stem portion 49 projects and in which the valvemember 41 is guided in its reciprocal movement. The side walls 30, 42,43 and -44 also have a second upwardly facing shoulder 62 positionedbelow the top wall 48 and above the shoulder 50 and against which ispositioned a plate-like member 53. The member 53 is apertured to receiveand guide a reduced stem portion -54 of the valve stem portion 49. Theplate-like member 5|, 53 cooperate to divide the chamber 39 into aplurality of smaller chambers 55, 56

, and 51, chamber 55 being the bottom or fuel oil is shown) are benttoward the inlet 21 from the shutter 29, one adjacent each of theaperture 32 side edges and both adjacent the aperture 32 bottom edge.The ears 33 have aligned apertures" therein for receiving a shaft 34. Asecond platelike shutter 35 overlies the aperture 32 of the shutter 29on the inlet'21 side thereof and has a pair of ears 36 projecting fromits side edges and adjacent its bottom edge (only one of which isshown). The ears 36 have aligned apertures through which the shaft 34extends so that the shutter 35 is pivotally carried by the shutter 29. Abolt-like threaded member 31 is secured to the shutter 35 adjacent itsupper edge portion and extends toward the inlet 21. A nut-like weightmember 38 is threaded on member 31 and biases the shutter 35 in anopening direction to open the aperture 32 for flow of air. The member 38may be moved back and forth to determine the biasing of the shutter 35.The shutter 35 is held in its position against the shutter 29 by thepressure of the air .within the conduit 22. Should the air pressure fallbelow a predetermined minimum,

the weight'member 38 will pivot the shutter 35 is separated therefrom bythe wall 30. The chamber 39 has an open top wall 40, a bottom wall 4|,and side walls 42, 43, 44 in addition to the common wall 36. The chamber39 is supplied with fuel oil by the conduit 26 which is connected to achamber inlet 45 openin through the side wall 42. adjacent the bottomwall 4|. The chamber 39 ha an outlet 46 positioned in and extending fromthe bottom wall 4| for connection with the conduit 2*. Flow through theoutlet 46 is controlled by means of a valve member 41 which cooperateswith a valve port 48 in the outlet 46. The valve member 41 has anextending valve stem portion 49 which projects upwardly through thechamber 39 substantially parallel to the si e Walls chamber, chamber 56being the intermediate or power element chamber, and chamber 51 beingthe top or adjustment chamber. The valve stem portion 49 is drilledconcentrically with it longitudinal axes to form a passageway 58 whichopens at its lower end below'the valve port- 48 and connects at itsupper end with a radially drilled hole 59 which communicates with theupper portion of the chamber 55, above the substantially constant fuellevel maintained therein by the con- 7 stant level device l9. Apassageway 66, in a boss integral with the wall 43, ha dts lower endopening into the outlet 46 audits upper end opening through the shoulder50 in alignment with an aperture through the member 5|. The member 53has an aperture or drilled hole 6| there'- through for maintaining thechamber 56 at atmosphericpressure. The passageways 58, 60 anddrilled'holes 59, 6| cooperate together to form a vent for the spacewithin chamber 55 overlyingthe liquid and also a vent for the outlet 46so that the outlet on the conduit 2 side of the valve port 48 willalways be maintained at atmospheric pressure. By maintaining atmosphericpressure in chamber 55 and in conduit 2 any relative variations inheight between the control device 3 and the burner 2 does not affect thefuel flow through the valve port 48. The plate-like member 53 has a pairof threaded apertures in which are threadedly secured a pair ofadjustably threaded stop members 64, 65 respectively. The stop member64, 65 have at their lower end portions, flanges 66, 61 which cooperaterespectively with upper and lower surfaces of an annular flange 68 ofthe reduced stem portion 54 to limit opening and closing movement of thevalve member 41. The stop member 65 may be set for any fuel flow whichwill burn with natural draft or air supplied at atmospheric pressure tothe burner 2. It must be remembered, however, that the stop member 65adjust the minimum burner operation and the burner 2 will thereforenever operate to supply less heat even though the thermostat l1 be in asatisfied position. The stop member 65 therefore should be properlyadjusted so that when the burner 2 is operating at minimum flowconditions it will not overheat the space i6.

The shaft 29' has a portion 69 which extends into the chamber 39 andmore particularly into the power element chamber 56. The extendineportion has rigidly secured thereto one end of a crank arm 10 whichterminates in an end portion 1| The side wall 44 is slotted, as at 1|;to provide clearance for the arm 10. A bos 12 projects from the wall 30into the power element chamber 56 and adjacent the wall 42. A fulcrumpin 13 1s rotatably carried within an aperture extending through theboss 12 and the wall 36 and substantially parallel to the wall 30 andterminates in a bifurcated end portion 16 which receives the end portionH of the crank arm carried by the shaft 29. A circular portion of thelever member is positioned intermediate the bifurcated end portion 16and the pivoted end portion 14 and is positioned between the annularflange .68 and a second flange 11 which, like annular flange 68, extendsoutwardly from the reducedstem portion 54 of the valve member 41 andwhich is spaced from and below the annular flange '68.

Positioned in the chamber 56 and secured to the side wall 42 thereof isone end of a supporting member 18 which carries at its other end thebimetallic element 19. The bimetallic element 19 is hook-shaped and hasa cylindrical portion 80 with a longitudinally split side wall. Oneedgeportion 8| of the split is secured to the supporting member 18 andthe other edge portion has a radially outwardly extending lip 82. Anelectrical heater means 83 is positioned within the portion 80 in heatexchange relation therewith and acts upon energization thereof to heatthe portion 80 so that it tends to open up and to raise the lip 82. Thelip 82 normally engages the upper face of a shoulder 84 formed on thevalve stem portion 49 at the intersection of the normal diameter portionwith the reduced diameter port on and limits upward movement of thevalve member 41. The heater means 83' is preferably of large mass sothat it has a slow rate of temperature change and acts to heat theportion 80, in response'to the average time the heater means isenergized, rather than being responsive to heat the portion only whenthe heater means is actually energized. The heater means 83 has leadwires '85, 85 which extend therefrom and terminate at binding posts 86,81 which are carried by a terminal block88. The block 88 is mounted,

as by screws, to the outside of the wall 42' and spaced therefrom by aspacer means 89.

Air pressure in the inlet 21 acts on the shutters 29, 35 to rotate theshaft 29 in a clockwise direction (see Fig. 4). Clockwise movement ofthe shaft 29 acts through the crank arm 10 to rotate the lever member 15in a counter-clockwise direction. Rotation of the lever member 15 in thecounter-clockwise direction acts to move the valve member 41 upward fromthe valve port 48 to allow greater flow of fluid from the chamber to theburner 2. Upward movement of the valve member 41 is limited byengagement of the shoulder 94 with the lip 82, and the lip 82 acts as avariable stop to limit the flow of fuel oil and air to the burner inaccordance with the temperature of the Space I0 as reflected by thethermostat l1.

The room thermostat I1 comprises a bimetallic responsive blade 90 whichcarries a contact member 9I cooperable with a fixed contact member 92 tocontrol an electric circuit in response to changes in temperature of theblade 90. Electrical energy from a suitable source of supply isconducted to the primary terminals of a transformer 93 by means of leadwires 94; -The transformer 93 has a secondary coil terminating interminals 95,96. Lead wires'91 are directlyconnected to the lead wires94 and to the electric motor'8 so that the motor 0 is supplied withelectrical energy for continuous operation. The

bimetallic blade is connected by means of a lead wire '98 to oneterminal of the transformer 93. The fixed contact member 92 isconnected, by means of a lead wire 99, to one binding post 96 of thecontrol device 3. The other bindin post 81 of the control device 3 isconnected by means of a lead wire I00 to one side of the limit switch I8which has its temperature sensitive element located within and sensitiveto the temperatures of air in the plenum chamber 6.. The

other terminal of the limit switch I8 is connected by means of a leadwire I0I to the ter-' minal 96 of the transformer 93. The thermostat I1also includes a resistance heater element I02 which acts uponenergization to heat the bimetallic blade 90 to cause the contact member9|,.

92 to separate and break th electrical circuit controlled thereby. Theheater element I02, un-

like the heater means 83, is one having a small mass so that it isquickly heated and cooled and heats the blade 90 more n arly in directaccordance to its energization or at a given predetermined rate. Oneterminal of the heater I02 is directly connected to the contact member92 and the other terminal of the heater I02 is connected by means of alead wire I03'to the terminal 96 of the transformer 93. The thermostatI1 is preferably so constructed that the bimetallic blade 90 is operableto close the contact members 9 I 92 at a minimum predeterminedtemperature and to open the contact members 9|, 92 ata maximumpredetermined temperature and the difference between the maximumpredetermined temperature and the minimumpredetermined temperature isthe differential temperature of the thermo stat I1. The heater I02 is sochosen that it will act upon continuous energization to heat thebimetallic blade 90 to a predetermined temperature above the surroundingair temperatur and which predetermined temperature is greater than thedifferential temperature of the thermostat I1. Due to the effect of theheater I02, the-blade 90 is made to part the contact members 9I, 92 in acycling manner until the temperature of the surrounding air reaches orexceeds the minimum predetermined temperature at which the blade 90 willmove the contact members 9|, 92 into circuit closed position. By soconstructing and arranging the heater I02, the heater means 83 and theblade 90; the thermostat acts in effect to modulate the flow of fuel andair tothe burner in accordance with the heating requirement thereof.

The operation of the burner apparatus may best be seen by giving anexample. Assume that the cut-in or the minimum predetermined temperatureat which the blade 90 moves contact members 9|, 92 together is 705 F.and the cutout or the maximum predetermined temperature at which theblade 90 moves contact members 9I, 92 apart is 72 F. The differential ofoperation is therefore 2 F. The heater I02 is so positioned and arrangedrelative to blade 90 that it will raise the temperature thereof theentire 2 F. in five minutes. Thus when the space I0 temperature lowersto 70 F. the blade 90 closes contact members 9|, 92 energizing heaterI02 and heater means 83. Without rise in the temperature of the spaceI0, the heater I02 would act, at the end of five minutes, to part thecontact members 9I, 92 and with temperature rise in space I 0, the timewould be somewhat shortened. In the five minutes or less interim,however, the heater means 83 will have increased somewhat in temperatureand heated the portion'80 of the element 19,

This heating will'cause the lip 82 to move upward slightly so that theair pressure in the conduit 22 will act to move the shutters 29, 35 toallow an increased flow of air to the burner. Movement of the shutter 20acts through shaft 29. crank arm and levermember to open the valvemember 41 in proportion to the rate of increase in the supplied air. Thelip 82, however, still continues to act as a stop and limits theincreased flow in proportion to the heating efiect imparted to thecylindrical portion 80 by the heater means 83.

Returning again to the action of the thermostat, the contact members SI,92, having deenergized the circuit to the heater I02, the blade 90 coolsrapidly, say in five minutes, and the blade 90 is again subject to thetemperature of the space I0. If the heating eifect of the burner 2 wassufficient to raise the space I0 temperature above 70 F., the contactmembers 9|, 92 remain parted. If, however, not enough heat has beensupplied, the contact members 9|, 92 will be moved together again by theblade 90 and the heater means will be given again a period of heating.If the space temperature dropped to say 67 F. and the heater I02 wasdesigned to raise the temperature of the blade only 4 F. on continuousenergization, the blade would be maintained at 71 F. and the heatermeans 83 would remain constantly energized so that after a given timethe lip 82 of element 19 will raise and allow the air pressure withinconduit 22 to move the shutters 29, 35 and valve member 41 until theflange 68 engages the flange 66 of the stop member 64 at which time theburner is operating at maximum flow capacity. Under the cyclingconditions, however, the heater means 83 is getting little bumps of heatand maintains an average temperature intermediate the maximumtemperature and that of the surrounding media. After a prolonged periodof deenergization, however, the heater means 83 will cool and the lip 82will lower to move the valve member 41 until the flange 68 engages theflange 61 of the stop member 65 at which time the burner 2 is operatingat minimum flre condition.

Should, however, the air pressure fall within the conduit 22 for anyreason such as pluggin of the orifice 23 or failure of the fan 1, theshutter 35 will fall forward due to the biasing effect of the weightmember 38 to open the aperture 32 and the shutter 24 will open so thatair under natural draft will flow to the burner 2. As the air pressureacting on the shutters 29, 35 is the sole means of opening the valvemember 41,- the valve member 41 will remain against the minimum firestop member 65 irrespective of the heating of the element 19 by theheater means 83. There is, therefore, no danger of the burner 2 beingflooded with fuel oil and burning with a sooty flame or of causing anexplosion. It may therefore be seen that. the burner apparatus isoperable to modulate the heating effect in accordance to the demand bythe space to be heated; will accurately proportion the relative amountsof air and fuel to maintain at all times the proper fuel-air mixture;requires no additional fan motor for supplying the burner; and willautomatically go to minimum flow natural draft conditions upon failureof the air pressure.

The circuit which is shown in Fig. 2 is diagrammatically that which isshown in Fig. 1 with the exception that the limit control has beenomitted.

Figs. 6, 1 and 8 show ajmodified'form of the control system in which afluid control has been used in place of the electrical control. Forsimplicity a natural convection heating furnace has been shown but thisfluid control could be used in a forced convection heating installationwith equal ease and,-if so used, the air circulating fan could be usedto furnish air to the burner, as in Fig. 1, instead of a. fan means I 05as shown. The parts of Figs. 6, 'l and 8, which are substantially thesame as the parts in the preceding figures,

are designated by the same reference characters.

In keeping with the showing of a natural con.- vection heating system,the outlet duct means II of the space I0 is connected directly to g theplenum chamber 6 in place of the duct I3. The fan means I05 supplies airunder constant pressure through a duct means I06 to the inlet 21 of thecontrol device 3. The control device 3 is operated by the fluid controlsystem which comprises a thermostat I01 positioned in and sensitive tothe temperature within the space I0, a pressure sensitive power elementI08 operatively connected to the control device 3 and a pressuregenerating bulb means I08 which is positioned in heat exchange relationwith the bottom wall IIO of the fuel burner fire pot 2I. The thermostatI01, element I08, and means I08 are communicatively connected togetherby a conduit means I I I.

The thermostat I01 comprises a cylindrical casing including a chamber II2 having a side wall II 3, and a lower end wall or bottomwall H5. Thebottom wall II5 has an aperture therethrough in which is sealed influid-tight relation one open end portion of the conduit means III forcommunication with the chamber H2. The side wall II 3 has an apertureII6 therethrough and the side wall II3 has a boss II1 projectinginwardly into the chamber II2 diametrically opposite and in alignmentwith the aperture II6. A bellows member II 8 has one end portion securedin fluid-tight relation, as at I I9, to the wall II3 around theperipheral edge .of the aperture H6. The other end of the bellows memberII 8 projects within the chamber H2 and is sealed in fluid-tightrelation to an end member I20. A closure member I2I overlies theaperture H6 and is held in fluid-tight relationship to the exteriorsurface of the wall II3 by solder I2I The bellows member H0 and endmember I20 cooperate to make the chamber II 2 a variable volumereceptacle communicating with the conduit means III through the bottomwall I I5. The volume of the chamber H2 is controlled by means of anadjustment screw I22 which is threadedly received in an aperturethroughthe closure member I2I. The screw I22 has a head portion I23external of the closure member I 2I which may be manually gripped forrotation of the screw I22 to adjust the volume of chamber II2. Ifdesired, an indicator may be secured to the screw I 22 and suitableindicia carried by the wall II3 to indicate the setting of the screwI22. The other end I24 of the screw I22 extends within a space I25defined by the bellows member II8, closure member I2I,- and end member I20, The end I24 is rounded and engages the end member I20 to hold itagainst movement due to the compression force of a helical coilcompression spring I26 which is held under compression between the wallII 3 and end member I20. The spring I26 has its end portions surroundingand held in position by the boss H1 and a boss I21 on the end memberI20. The spring I26 acts to maintain the end member I20 at all times inengagement with the end I24, and

needs to exert a greater force than the innate resilient force of thebellows member [I8 so that as the screw I22 is moved inward into thespace I25, the bellows II8 will expand and upon outward movement of thescrew I22 the bellows will compress.

A second portion of the conduit means III is sealed in fluid-tightrelation to an aperture in the bottom wall of a cup-shaped casing I28 ofthe power element I08 and is in communication with the interior thereof.The power element I08 comprises the casing I23 which has an out-turnedflange portion I29 secured to the wall 42 of the control device 3, abellows member I30 and a thrust member I3 I. One end portion of thebellows member I30 is sealed in fluid-tight relationship to the innerperipheral edge of an annular ring member I32 which has its outerperiphery sealed in fluid-tight relationship to the inner wall of thecup-shaped casing I28 adjacent the open end thereof. The other end ofthe bellows member I30 extends inwardly into the casing I26 toward thebottom wall thereof and is sealed in fluid-tight relationship to an endmember I33. The casing I28, bellows member I30, end member I 33 and ringmember I32 cooperate to form a sealed pressure responsive chamber I34.The thrust member I3I comprises a cylindrical member I35 having aconcentric bore I36 therethrough. A portion I31 of the bore I36 is ofenlarged diameter and opens through one end of the member I35. Arod-like thrust member I31 is reciprocal within and fits within the boreI36 and has one end portion extending beyond the member I35 and securedto the end member I33. The other end of the rod-like member I31 extendsinto the enlarged diameter bore portion I31 and has a head portion I38which is operable to reciprocate within the portion I31 but is urgedagainst a shoulder formed at the intersection of the enlarged diameterbore portion I31 and the normal diameter of the bore I36 by ahelicalcoil compression spring I39, which spring I39 is also positionedwithin the bore portion I31.

The spring I39 is held under compression and against the head portionI38 by an abutment member I40 threaded into the open end of the enlargeddiameter bore portion I31. A conical end portion I4I of the member I40extends beyond the cylindrical member I35 and is received within aconical recess I42 of a vertically extending arm I43 of a bell-cranklever member I44 pivoted, as at I45, to a bos I46 which extendsoutwardly from the chamber wall 30. The horizontal arm I41 01 thebell-crank lever member I44 abuts the upper face of the shoulder 84 ofthe valve member 41 and acts to limit upward movement thereof similarlyto the lip 82 of the bimetallic element (shown in Fig.4). The spring I39holds the head portion I38 against the shoul-' der with a force greaterthan any normal force exerted by the power element I08 so that normallythe thrust member I3I acts as a rigid member but which upon abnormalpressure ex- ,erted by the power element I08 acts to collapse to relievethe pressure within the chamber I34 without a corresponding movement ofthe lever member I44. The power element I08 also includes a helical coilcompression spring I48 positioned within the bellows member I30surrounding and concentric with the member I3I, One end of the springI48 abuts the end member I33 and its other end abuts the outer surfaceof the wall 42. The spring I43 acts to oppose collapsing movement of thebellows member I30 in its movement of the valve member 41 toward closedposition. I

A third portion of the conduit means III is communicatively conhected tothe bulb means I09 and which bulb means acts to provide the pressure forthe control system. The bulb means I09 is positioned within a well I49of a heat conducting member I49 which has a portion secured in heatexchange relation with the bottom wall I I0 of the lite pot 2I.

The chamber II2, power element I08 and the conduit means III is at alltimes maintained substantially completely: filled with a temperaturesensitive volatile liquid, the pressure of which is controlled by thebulb means I09 as will be described hereinafter. There beingsubstantially no flow through the system thevapor pressure pressurewithin the inlet 21 of the control device 3 as the shutters 29, approachclosed position, additional pressure in bulb means I09 is necessary asthe valve member 41 approaches minimumflow condition. It will also benoted that as the bellow I30 collapses, the chamber I34 increases involume which will tend to allow fluid to escape from the bulb means I09to decrease the pressure therein. The final system pressure and positionof the power element I08 will be a position of equalization of pressurewithin the means I09 and element I08.

The operation of the control system is as follows: As the liquid withinchamber II2 increases in volume with increase in its temperature due toincreasing temperature within the space I0, a quantity of. the liquid isforced from the conduit means III into the bulb means I09 where it isvaporized by the heat conducted to the bulb means I09 through the memberI49. This will increase the pressure within the bulb means I09 and betransmitted to the liquid in the conduit means II and chambers H2 andI34. Increased pressure within the chamber I34 causes the end member I33to compress the spring I48 to move the thrust member I3I to rotate thebell-crank member I44 in a clockwise direction (see Fi 8) until abalance of force again occurs as was set forth hereinbefore. Additionalrise in temperature of the liquid within chamber I I2 causes 3additional liquid to be elected from the conduit means III into the bulbmeans I99 to increase the pressure acting .on the liquid in the conduitmeans III and chambers II2, I34.

Upon cooling of the chamber II2 liquid is received therein from theconduit means I II which allows fluid to escape from the bulb means I09thereby lowering the pressure within the bulb means I09 and the chambersII2, I34 so that the shutters 29, 35 and the valve member 41 can open.The expansion and contraction of the liquid in the chamber H2 is verygradual and continuous and it, therefore, may readily be seen that thevalve member 41 will be modulated throughout its range of movement todecrease and increase the output of burner 2 in response to change intemperature of the space I0.

'bottom wall I65 of the chamber ISI.

Should the adjustment screw I22 be rotated manually throughout its rangein a temperature lowering direction, considerable liquid will be ejectedfrom the conduit means III into the bulb means I09 due to the decreasein volume of chamber II2. Because of the large amount of liquid ejectedinto the means I09 and the restricted rate of flow of heat to the bulbmeans I09 through the member I49 it will take considerable time tovaporize the liquid to increase the pressure enough to move the valvemember 41 and shutters 29, 35 to closed position. This lag shouldpreferably be sufficiently great so that the valve member 41 andshutters 29, 35 will slowly move toward closed position possibly takingtwo minutes or longer thereby to prevent a smoky flame which resultsfrom immediately stopping the flow of air before the fuel pool in thepot 2I is consumed.

The operation of the apparatus shown in Figs. 6, 7 and 8 issubstantially the same as explained in respect to the preceding flguresexcept for the change in the air supplying means, and the controlsystem, as set forth hereinbefore, and a further description is deemedunnecessary.

In Figs. 9, 10 and 11 there is shown a modification of my device inwhich the mechanical interconnection between the air controlling meansand the fuel controlling means is maintained but instead of thecontinuously throttling type of fuel control there is shown an apparatuswhich modulates the output in steps. A chambered casing I 50 has anupper or control chamber II, a lower or constant level fuel oil chamberI52 positioned below the control chamber I5I and an air flow passagewayor chamber I53 which is positioned above the constant level chamber I52and beside of the chamber I5I, with a wall I54 in common with thechamber I 5I. A plate-like supporting member I55 for the modifiedcontrol apparatus, to :be hereinafter described, is positioned withinthe chamber I5I and has a plurality of upturned flanges or supportingportions I56, I51 from its side edges and has flange portions I58, I59extending upwardly from its end edge portions. The flange portions I56,I51 are respectively secured to the protuberances I60, I6I projectinginwardly from side walls I62, I63,of the chamber I5I by suitable means,such as screws. The end flange portion I59 is suitably secured to thecommon wall I54 and holds the bottom portion I64 of the plate-likesupporting member I55 in a substantially horizontal position parallel toa The wall I54 and end flanges I58, I59 have aligned aper- .tures inwhich a shaft I66 is journaled for rotational movement. A portion I51 ofthe shaft I66 extends into the chamber or air flow passageway I53 andrigidly carries a cam member I68 for cooperation with one face of abutterfly damper or shutter I69, pivoted at its upper edge portion, asat I10, to the top wall "I of the chamber I53. The shutter I69 is biasedtoward open position by a helical coil tension spring I12 which has oneend rigidly secured, as at I13, to the top chamber wall I1I of thechamber l53 and which has its other end secured, as at I14, to the faceof the shutter I69 opposite to that engaged by the cam member I69. Thechamber I53 has open end walls I15, I16 and the open end I16 isconnected to the inlet side of a fan or air supply means I19 which isused to supply air to the fuel burning apparatus, such as the fuelburner 2 (shown in Fig. l) The open end wall I15 may be opened to andsubjected to atmospheric pressure so that when the fan means I18 is inoperation the atmospheric pressure acts on the shutter I69 and urges itagainst the force of the helical coil spring I12 toward closed position.Referring again to the chamber I5I and the platelike supporting memberI55, it will be seen that the bottom portion I64 has a pair of upturnedfingers I19, I90 which carry a medium fire and a high flre bimetallicpower element 'I8I, I92 respectively and which elements are preferablyhook-shaped in form and have cylindrical portions I93, I94 respectively.The portions I93, I84 are longitudinally split to form side wall endportions I95, I85 and I81, I88 respectively. Lip or power transmittingportions I91, I98, respectively, extend radially outward from portionsI91, I89. The end portions I85, I96 are secured to the fingers I 19, Iand support the bimetallic power elements I81, I92 rigidly with themember I55.

A valve member I99, positioned within chamber the conduit 2 forcontrolling the flow of fueloil to the burner 2. The valve member I99has a stem portion I9I which projects upwardly from the chamber I52through an aperture in the bottom wall I 65 into the chamber I5I andterminates in a reduced diameter end portion I92. This portion I92 isguided i'or reciprocal movement with in an aperture extending through aprotuberance or boss I93 projecting inwardly from the side wall I62. Thereduced diameter end portion I92 has a pair pi spaced annular outwardlyextendin flanges I94, I95. Screw-threaded within apertures in theprotuberance I93 are a pair of stop members I96, I91 having flanges I99(only one of which is shown) which cooperate with the under and uppersurface of the flange I94 to limit reciprocal movement of the valvemember I99 and controls the minimum and maximum flow of fuel oil to theburner 2. A third stop memberv I99 is threadedly secured to a plate-likemember 200 which is secured by means of a screw to a protuberance 20Iwhich projects inwardly within the chamber I 5| from the wall I54. Thelip portion I91" upon its upward movement engages the stop member I99which limits the upward movement of portion I91 and its lip portion I91to determine the intermediate flre operation. The high flre bimetallicelement I 92 is operatively connected to the shaft I66 for movementthereby in one direction by a,lever member 202 rigidly secured to theshaft I66 and which has'an extending arm portion 203 operable to engagethe upper surface of the element lip portion I99. A second lever member204 is pivotally connected to the shaft I66 and has an arm portion 205which is received intermediate the flanges'l94, I95 and has a secondPortion 205 which overlies a portion 205'" 'of the lever member 202. Thelever member 204 is connected to the lever member 202 by an adjustmentmechanism comprising a threaded screw 206 which is loosely receivedwithin an aperture in the-lever member portion 205" and is threadedwithin an aperture in lever member portion 205*. A helical coilcompression spring 201 surrounds the screw 209 and is placed undercompression between the lever member portions 205, 205 and acts to urgethe lever member portion 205 against the head of the screw 206. Thebimetallic power elements I9I, I92 are actuated by a pair'of electricheating units 209, 209 positioned within the cylindrical portions I93,I94 respectively, .of the bimetallic elements I8I, I92. The units 208,209 act to heat the bimetallic elements so that the portions I83, I84will open up thereby moving the lip portions I81, I88 in an upwarddirection. Upon upward movement of the lip portion I81 it engages theunderside of the flange I95 to lift the valve member in an openingdirection and is limited in its movement by the engagement of the lipportion I81 with the lower end of the stop member I99. Upward movementof the valve member, due to the positioning of the arm portion 205 oflever member 204 between the flanges I94, I95, acts to rotate the levermember in a clockwise direction (see Fig. 11) and the cam member I68 tocoact with the face of the shutter I69 to force the shutter I69 againstthe air pressure in the passageway I53 to allow floWof air therethroughto the inlet of the fan means I18. By correctly proportioning the camsurface and the valve member I89, the relative flows of oil and air maybe accurately controlled so that the correct proportion of each forproper combustion may be admitted to the fuel burner 2. Uponenerglzation, the heating unit 209, which is the high fire heater, actsto heat the cylindrical portion I84 so that the lip portion I88 movesupward to engage the arm portion 203 of the lever member 202 to rotatethe shaft I66 further in a clockwise direction. Further movement oftheshaft I66 causes the shutter I69 to move to a further open position,and causes the valve member I 89'to move to a further open position tosupply additional fuel corresponding to the additional air supplied tothe fuel burner 2. The flange I95 will, under high fire conditions, bespaced above the lip portion I81. 3

The heating units 208, 209 are electrically connected in the followingmanner: The unit 208 is connected by means of lead wires 2I0, 2 tobinding posts 2I2, 2I3 respectively carried by a terminal strip 2I4secured in a suitable manner externally of the chamber I5I to the sidewall I63 and the unit 209 is connected by means of lead wires 2I5, 2I6to the' binding post 2I3 and to a binding post 2I1 respectively, thebinding post 2I1 being carried by the terminal strip 2I4. A transformer2I8 has its primary coil connected by means of lead wires 2I9 to asource of electrical energy and has its secondary coil 220 connected toterminals 22I, 222. A lead wir 223 connects the terminal 222 to thebinding post 2I3 so that oneside of the heaters 208, 209 are connecteddirectly to one side of the transformer secondary coil 220. The otherterminal 22I of the transformer 2I8 is connected by means of a, leadwire 224 to a thermostat, diagrammatically shown at 225, and'which maybe positioned within the space heated by the burner 2. The thermostat225 comprises a bimetallic blade 226 which is directly connected to thelead wire 224, and which carries a pair of contact members 221, 228, thecontact member 221 being secured to the blade by a spring member 221 andthe contact member 228 being directly secured thereto.

The members 221, 228' cooperate respectively with a pair of stationarycontact members 229, 230. The contact members 221, 229 act to completean electric circuit at a higher blade temperature than the bladetemperature necessary to close the contact members 228, 230. The contactmember 229 is connected by means of a lead wire 23I to the binding post2I2 and the contact member 280 is connected by means of a lead wire 232to the binding post 2I I.

The operation of the modification in Figs. 9,.

and 11 is as follows: The fan means I18 is continually operating and thesuction created thereby causes the atmospheric pressure to act on theshutter I69 to hold it in engagement with the cam member I68. If thethermostat 225 is satisfied or in open circuit condition, as shown, theshutter will be in nearly closed position, as shown in Fig. 11. Upon adecrease in temperature in the space and of the blade 226, the contactmembers 221, 229 will be moved into engagement. This closes anelectrical circuit from the terminal 22I lead wire 224, blade 226,contact members221, 229, lead wire 23I, binding post 2I2, lead wire 2I0,heating unit 208, lead wire 2I I, binding post 2I3 and lead wire 223 tothe terminal 222. Upon closure of this circuit the heating unit 208heats the cylindrical portion I83 and the lip portion I81 will moveupwardly lifting the valve member I89 until the lip portion I81 engagesthe stop member I99 which limits the opening movement. Upward movementof the valve member I89 acts through lever member 204 to rotate theshaft I66 and cam member I68 to move the shutter I69 against the forceof the atmospheric pressure to allow for increased air flow to theburner 2 in proportion to the increased fuel oil flow. Should the burneroutput'not be suilicient to maintain the-space temperature and thetemperature should fall to a predetermined lower temperature, thecontact members 228, 230 will engage. This energizes a second circuitfrom the terminal 22I through lead wire 224, blade 226, contact members2281 230, lead wire 232, binding post 2I'I, lead wire 2I6, heating unit209, lead wire 2I5, binding post 2I3, and lead wire 223 to the terminal222. Energization of the heating unit 209 acts to heat the cylindricalportion I84 and thereby to move the lip portion I88 upward to engage thearmportion 203. Continued upward movement of the portion I88- acts tomove the lever member 202 to rotate the shaft I66. Rotation of the shaftacts through the arm portion 205 to lift the valve member until theflange l94 engages the stop flange I 98 of the stop member I91 to limitits 4 increased flow of fuel oil.

Upon opening of either of the sets of contact members 228, 230 or 221,229, the connected heating units 209, or 208 respectively, will coolalong with the cylindrical portions I84 or I83 so that the air pressureacting .on the shutter I69 will act through the cam member I68 to rotatethe shaft I66 in a counterclockwise direction (see Fig. 11) therebymoving the shutter I69 and moving the valve member I89 toward closedposition. It will, therefore, be seen that inthe modified form ofthdapparatus the power elements act to open the valve and acts as astopto limit closing movement of the valve member and shutter by the airpressure in the chamber I53.

In case of failure of the air supplyingv means I18 the pressure acrossthe shutter I69 will decrease and the spring I12 will move the shuttersaid burner, means for supplying air under pres-, sure to said burner,air pressure positioned damper means for controlling the flow of air tosaid burner from said supplying means, lever means mechanicallyinterconnecting said fuel controlling means and said air controllingmeans, automatic means operable to control the positions of both saidfuel controlling means and said air controlling means solely when saidair'supplying means is effective thereby to maintain emcient operationof said burner, and means operable independently of said automatic.means for rendering said air controlling means ineffective to controlthe flow of air upon failure of said air "supplying means.

2. In an apparatus of the character described, a fluid fuel controllingmeans, an air flow controlling means, a shaft member, meansinterconnecting said fuel means and said shaft means, an abutment memberconnecting said shaft means and said air means, said air means being sopositioned and related to the air pressure that said air means is heldthereby against said abutment member, and means acting to urge said airmeans out of engagement with said abutment member and operable upon apredetermined low pressure of the air controlled by said air means.

3. In an apparatus of the character described, a fluid fuel controllingmeans, an air flow controlling means, a shaft means, meansinterconnecting said fuel means and said shaft means, an abutment memberconnecting said shaft means and said air means, said air means being sopositioned and related to the air pressure that said air means is heldthereby against said abutment member, means acting to urge said airmeans out of engagement with. saidabutment member and operable upon apredetermined low pressure of the aircontrolled by said air means, andpower means acting on said fuel means to move said fuel means and saidair means against the force of the air pressure.

4. In a device of the character described, a fuel supply chamber havingan inlet and an outlet, a control chamber positioned above said supplychamber, a valve member controlling flow through said outlet and havinga portion extending upwardly through said fuel chamber into said controlchamber, an air controlling means, mechanical means interconnecting saidvalve member and said air means, a heat actuated thermostatic elementpositioned within said control chamber and operable to move said aircontrolling means in one direction, a heat actuated means within saidcontrol chamber, and lever means actuated by said heat actuated meansand operable through said connecting means to move said air controllingmeans further in said one direction.

5. In a device of the character described, a fuel supply chamber havingan inlet and an outlet, a control chamber positioned above said supplychamber, a valve member controlling flow through said outlet and havinga portion extending upwardly through said fuel chamber into said controlchamber, an air controlling means, mechanical means interconnecting saidvalve member and said air means, a heat actuated thermostatic elementpositioned within said control chamber and operable to move said aircontrolling means in one direction, a heat actuated means within saidcontrol chamber, lever means actuated by said; heat actuated means andoperable through said connecting means to move said air controllingmeans further in said one direction, and means responsive to a conditionof the air to render said heat actuated means ineffective to move saidair 0on trolling means.

6. In a liquid fuel burner control apparatus, a constant level liquidfuel chamber having an outlet and having an inlet, a control chamber, afuel valve controlling flow through said outlet and having a stemportion and having a projecting portion, stop means engageable by saidprojecting portion for limiting movement ofsaid valve in an openingdirection, air controlling means for regulating the flow of air to theburner, mechanical means operable to control said air means andinterconnecting said valve and said air means, said mechanical meansbeing operable upon movement in one direction to move said valve in aclosing direction, power means limiting movement of said mechanicalmeans in said one direction, a heat actuated power element, and a levermember moved by said power element and operable to limit movement ofsaid mechanical means in said one direction, said power element beingoperable through said lever member and said mechanical means to controlsaid air means.

7. In a liquid flow burner control apparatus, a constant level liquidfuel chamber having an outlet and having an inlet, a control chamberoverlying said fuel chamber, a fuel valve controlling flow through saidoutlet and having a stem portion extendinginto said control chamber andhaving a projecting portion; stopmeans engageable by said projectingportion for limiting movement of said valve in an opening direction, aircontrolling means for regulating the flow of air to the burner,mechanical means operable to control said air means and interconnectingsaid valve and said air means, said mechanical means including a levermember, said lever member being operable upon movement in one directionto move said valve in a closing direction, heat actuated power meanslimiting movement of said lever member in said one direction, stop meansengageable by said power means to limit movement thereof uponenergization, a heat actuated power element, a lever member moved bysaid power element and operable to limit movement of said first-namedlever member in said one direction, said power element being operablethrough said second-named lever member and said mechanical means tocontrol said air means, and means operable upon a conditioncorresponding to lack of air to render said power element ineffective tocontrol said air means.

8. In a burner system for heating a space, a fuel control valve, meansfor moving said valve toward open position, a first fluid containerpositioned within and responsive to the temperature of the space, asecond fluid container positioned in thermal relation with andresponsive to the temperature of the burner, a pressure sensitive meanshaving an operating element, means connecting said containers and saidsensitive means to form a sealed interconnected system, a temperaturesensitive volatile fluid within said system, said fluid being so relatedto said system that said connecting means and said first container andsaid pressure means are substantlally completely filled with liquid atall times, said fluid which is in said second container being so relatedthereto that all of said fluid may be in a vaporous state, the pressureof said vaporous fluid acting to determine the pressure of said fluidwithin said system, and means operatively connecting said operatingelement and said valve to limit movement thereof by said moving means inaccordance with the pressure of said fluid within said second container.

9.'In a burner system for heating a space, a

fuel control valve, means for moving said valve toward open position, aflrst fluid container positioned within and responsive to thetemperature of the space, a second fluid container, means having apredetermined rate of heat transfer for transmitting heat from theburner to said second container, a pressure sensitive means having anoperating element, means connecting said containers and said sensitivemeans to form a sealed interconnected system, a temperature sensitivevolatile fluid within said system, said fluid being so related to saidsystem that said connecting means and said first container and saidpressure means are substantially completely filled with liquid at alltimes, said fluid which is in said second container being so relatedthereto that all of said fluid may be in a vaporous state, the pressureof said vaporous fluid acting to determine the pressure of said fluidwithin said system, and means operatively connecting said operatingelement and said valve to limit movement of said fuel controlling meansagainst the force exerted by said pressure responsive oxygen controllingmeans, and means for. rendering said sensitive means ineffective toactuate one of said controlling means upon a predetermined reduction inpressure of the oxygen available in said supplying means.

ment thereof by said moving means in accordance with the pressure ofsaid fluid within said second container.

10. In a burner systemv for heating a space, a fuel control valve, meansfor moving said valve toward open position, a first fluid containerpositioned within and responsive to the temperature of the space, asecond fluid container positioned in thermal relation with andresponsive to the temperature of the burner, a pressure sensitive meanshaving an operating element, means connecting said containers and saidsensitive means to form a sealed interconnected system, a temperaturesensitive volatile fluid within said system, said fluid being so relatedto said system that said connecting means and said first container andsaid pressure means are substantially completely filled with liquid atall times, said fluid which is in said second container being so relatedthereto that all of said fluid may be in a vaporous state, the pressureof said vaporous fluid acting to determine the pressure of said fluidwithin said system, means operatively connecting said-operating elementand said valve' to limit movement thereof by said moving means inwaccordance with the pressure ofsaid fluid within said second container,and means operable upon a predetermined abnormal pressure within saidsystem to reduce said abnormal pressure.

11. In a fluid fuel control apparatus, a fluid fuel burner, means forcontrolling flow of fluid to said burner, means for supplying oxygenunder pressure to said bumer, means for controlling the flow of oxygenand operable to exert a force proportional to the pressure of theoxygen, mechanical force transmitting means interconnecting said fuelcontrolling means and said oxygen controlling means and operable tomaintain predetermined relative movement therebetween for proportioningthe relative flow of the oxygen and flow of the fuel, saidv forcetransmitting means being operable to transmit the force of said oxygencontrolling means to said fuel controlling means, means sensitive to theoutput of said burner and operable to regulate the move- 12. In anapparatus of the character described,

in combination a fuel flow controlling valve and an air flow controllingvalve, means for establishing apressure differential across said aircontrolling valve, means interconnecting said valves and operable toprovide predetermined relative movement therebetween, means for movingsaid valves toward open position, and means operable upon apredetermined reduction in said pressure differential for rendering saidinterconnecting means ineffective to maintain said predeterminedrelative movement.

13. In an oil burner control apparatus, a duct for flow of air to theburner, a pressure responsive air valve having an opening therethrough,

a pivoted valve plate closing said opening and movable to open positionupon reduction of air pressure-said valve regulating the supply of airto the burner and eccentrically mounted within said duct to be urgedtoward open position due to the force of the air impinging thereon,means controlling flow of fuel to the burner; means interconnecting saidair valve and said fuel controlling means so that movement of said airvalve to supply more air to the burner acts to move said fuelcontrolling means to supply more fuel to the burner, and thermostaticmeans actuated in accordance with the output of the burner andmechanicallycooperating with said fuel means to determine the positionto which said fuel means is movable by said air valve.

14. A fluid fuel burner control device comprising a casing having apassageway therethrough for flow of fluid fuel and having a passagewaytherethrough for flow of combustion supporting air, means for propellingair through said air passageway, a reciprocal fuel valve in said fuelpassageway, an air valve responsive to air pressure and controlling airflow through said air passage, automatic means actuated in accordancewith temperature change and operable to control the opening movement ofsaid fuel valve, and means relating the position to which said air valveis moved by air pressure to the position to which said fuel valve ismovable under the control of said automatic means.

15. A fluid fuel burner control device comprising a casing having apassageway therethrough for flow of fluid fuel and having a passagewaytherethrough for flow of combustion supporting air, means for propellingair through said air passageway, a reciprocal fuel valve in said fuelpassageway, an air valve responsive to air pressure and controlling airflow through said air passage, automatic means actuated in accordancewithtemperature change and operable to control the opening movement of'said fuel valve, means relating the position to which said air valve ismoved by air pressure to the position to which said fuel valve ismovable under the control of said automatic means, and means cooperablewith said air valve to establish an open air flow path through said airpassageway upon failure of said propelling means.

WALTER S. LANDON.

